This disclosure relates to a bearing assembly and, more particularly, to a ball bearing assembly for a gas turbine engine.
A gas turbine engine includes various rotating components, such as shafts for example, which drive fan components and blade components associated with compressor and turbine sections of the gas turbine engine. Various types of bearings can be used to support the shafts for rotation relative to non-rotating engine structures.
For example, ball bearings can be used to support rotor shafts. In particular, split-race angular-contact ball bearings are often utilized due to their high thrust load capability and high reliability. The split-race bearing includes a one-piece outer race and a two-piece inner race with each inner race piece being separated at a split. Known split-race inner race ball bearings are designed to include a gothic-arch that is created by a discontinuous curved surface provided by the inner race pieces. During manufacturing, a shim piece is positioned between the inner race pieces, and both pieces are then machined to have curved surfaces with a common center point. After machining, the shim is removed and the pieces are assembled to provide the gothic arch. Optionally, the two inner races can be machined separately to have a common radius of curvature.
The gothic arch configuration prevents a ball bearing element from contact with the split, break-edges at the split, or radial oil slots when there is no thrust load and a very light radial load. When the ball bearing element contacts the split, high stresses can be produced at the contact area. Due to high stresses encountered when ball-to-split contact is made, traditional split race bearings are utilized only in conditions where there is thrust load applied under heavy radial loading. As such, traditional split race bearings are not used for applications where pure radial loading conditions could occur.
Accordingly, there is a need for a split-race bearing that can take advantage of high thrust load capability as well as being able to accommodate pure radial loading under high radial load conditions.